Mystery: M62TU sucking oil. PCV replaced. Still burning oil. Help diagnose?

[gmc90]

Hoping my engine isn't a goner. Help?

About 5K miles ago, I overhauled my 2003 540’s engine @ ~185K miles. It was leaking oil from everywhere, so I resealed and reworked the typical stuff. Timing chain guides, VANOS replaced (Dr. VANOS), new timing chain, new OSV, new pieces and parts here and there, new seals everywhere. I didn’t replace PCV (dumb) but had zero burning oil before the re-seal. I had professional help by trained ex-BMW mechanics guiding me, and they basically set the timing themselves with me watching.

Engine ran great, and quiet, for a while, then started not to.
- Fuel economy was slightly worse after the re-work. Where I used to avg 22-23 mpg on a tank, now I was 21. Not terrible, but I noticed it.
- I began to get intermittent VANOS codes, mostly bank 1, sometimes bank 2.
- Started to get the typical bad VANOS rattle.
- I started getting times when the engine would not start, when warmed up. Start from cold – fine, always – then drive a while, stop somewhere, and car wouldn’t start with a warm engine. The starter would engage, but it was like it wasn’t strong enough to turn the engine over. One time, I left the car overnight, and it started from cold. There were times when it started from warm, but it just sounded like the starter was laboring.
- My mechanic & friend, who’s worked at BMW dealers and is now indy, recollected sometimes VANOS would go bad and “lock” in (advanced?) position.

And – it had started burning oil like a banshee. I’d burn a quart every 500 miles by time I started work again.

Given the VANOS codes, and the engine-warm lock-up events, I asked Dr. VANOS for replacement VANOS wheels and he sent them under warranty, no questions asked (shameless plug…even if his first set might not have worked for me. A pleasure dealing with him.)

Pulled engine apart, re-did VANOS, set timing. I pulled off intake manifold to do PCV valve – its torx bolts were NOT coming off, and I wanted to look inside the intake anyway.
- Old PCV diaphragm looked fine – clean, intact.
- Possibly very telling: Oil I drained was ugly. Gunky, like I’ve never seen it before. There was something in it that was not supposed to be.
- W/ dropped lower oil pan, I blew air lightly into OSV tube poking into the lower sump, and it didn’t seem like anything was clogged whatsoever.
- There was plenty of oil inside the intake.

Started it up yesterday:
- Ran very smooth. One cylinder misfiring, plug looked just OK, I think I just need a new coil – it’s original @ 190K miles (still have 5 of 8 original coils). Still, it ran quiet, no real tapping noises. Could of course be a fouled plug.
- But still burned oil…huge amounts. Did so cold & warm. Huge trail of oil smoke on the road during testing. Oil smoke in exhaust increased greatly as RPMs increased.
- No obvious vacuum at dipstick. Put my fingers over it, no discernable sucking.
- I pulled intake off again. Obvious oil inside the intake again, and oil literally pooled inside #7 cylinder atop valves. Oil trails (that I didn’t see before) not below valves (as I’d expect if seal leakage) covering the intake port.

I’m trying to figure out how all the oil is getting to intake.
- I don’t *think* it’s just bad valve guide seals. Others will know better, but don’t bad valve guides usually leak oil mostly when cold? And – this much? And – bad valve guide seals won’t get me oil in intake, right?
- If there’s no vacuum at dipstick, doesn’t that say something is keeping vacuum from sucking from the crankcase? If so…where is this oil coming from that’s reaching the intake?
- I replaced OSV during initial reseal, inside lower timing cover, and all the parts connecting it to the tube going to PCV. I blew air through it a small bit – seemed fine. But remember the gunky oil? Could that clog an OSV?
- I didn’t replace any of the other vacuum or secondary air components. No evidence of vacuum leaks though, and brake boost was fine (which comes from PCV vacuum take off, correct?)
- Wish I knew source of gunky oil. Suspect perhaps inside of valve covers, which I had blasted and exteriors powdercoated. Not certain of this at all though.

Help? I love my car and want to put another 100K on it – hence the reseal in the first place.

[Kenny1958]

I'm in a similar predicament.

I've done a supercharger install using the Jag blower and consequently do not have the PCV at the back of the manifold. I have installed a catch can in the usual way and plumbed it so that it drains back to the engine via the rubber line coming out of the oil filter housing.
We have been struggling to stop the the motor running lean and after a while running the catch can fills with oil luckily draining back on its own, i'm wondering if the oil separator in the timing case has given up and is sending oil instead of oil vapour to the catch can.
Anyway i'll probably know soon as i'm stripping down the front of the engine gonna do the guides and the separator

[edjack]

Measure the crankcase vacuum; s/b 3-5 water inches.

Do a leakdown test.

Bad valve guides typically cause oil burning when decelerating and subsequent accelerating, due to engine vacuum sucking oil into the combustion chamber.

Bad rings will cause oli burning when running at steady speed.

[gmc90]

Well, I got everything back together again, been driving around. Am getting codes for misfires in various cylinders, but the engine runs smoothly...not that I am doubting the codes. *Most* of the coils have been replaced over time, so I looked at plugs, and #7 (back of engine nearer to PCV) plug fouled severely, other plugs pretty good. Good amount of oil burning after decel/stopping, then acceleration...certainly thinking bad valve guides. Crap.

I'll do a leakdown test. Do bad valve guide seals cause leakdown?

190K miles. I'm not paying for a valve guide seals job on this motor and it's beyond my power to do it myself. Otherwise, my 540 is in exquisite shape...all suspension redone, interior perfect, exterior looks 3 years old not 13...so a question:

Am I crazy to be thinking of putting a new motor in this car, from some salvage yard? That IS within my/my buddy's capability. The CAR has a lot of life in it, even if motor doesn't.

[Mach540]

How's your coolant level been?
Any chance the coolant pipes under the intake leaking, gumming up your oil and vanos and causing all this rukus?

[gmc90]

Thanks for responding. Nope, no coolant issues. I pulled intake off, everything in the valley looked good. When I did the re-seal, I of course did a valley pan job.

I'm going to drive ~100 miles, change oil and get it analyzed. I keep thinking of that nasty gunk in the oil. Not good.

[Msport540]

Did you replace the oil separator when doing the guides? I have a sad feeling it's going to be rings or stem seals, just get a compression gauge and check each cylinder, it won't take long.

[gmc90]

yep, I sure did replace the separator. I'm tellin' ya, I did pretty much everything you can do to this engine without taking off heads/taking apart the bottom end.

If leakdown is bad, what do you think is a better option for a car I HAD wanted to drive another 100K: find a not-too-used engine (appears there are many), or have rings and/or valve seals done? If I had not bitten off all the suspension, interior, ancillary engine bay stuff in the last year, I'd just give up (again, assuming its one of those bad things).

[brybe]

Any updates?

[gmc90]

I did a dry compression test, 165 psi, +/- less than a couple psi, all cylinders. Didn't bother with wet test, and didn't go through the effort of a leakdown.

I took off the throttle body, and took pictures and swabbed inside the intake. LOTS of oil inside the intake, especially towards the back of the intake. Hmmm.

Car is with my indy mechanic now. I'm driving a spare. My current thoughts:
- Oil consumption certainly could be bad valve guides, but this much oil? Could be lower end issues too but I just doubt that is the whole story.
- So it sure feels like a PCV or crankcase vent system issue. Why else is there going to be oil in the intake? PCV valve replaced with a brand new one that I assume is good.

I'm at a loss, figurative and perhaps literally.

[1stoutm5]

Toss that CCV and go catch can, the CCV/OSV design on these engines SUCK!! SUCK oil that is.

[gmc90]

I've seen some threads on it. Have you done it yourself?

Why would it go bad all of the sudden?

[Calli74]

Did this thread die? Or revitalize elsewhere? Any updates?

[SergeBMW]

Any updates would be fantastic. I'm in the same place with my E38 M62. New OSV and PCV, ran fine for a few months then started smoking. Replaced the PCV with again another, same issue. Now its smoking non stop. Not crazy but if you look at the exhaust you can see/ smell oil burning. Coolant and oil is clean.

[JimLev]

Serge, did you use a BMW CCV?
The knock offs don't last.

[SergeBMW]

I used one from MEYLE, was amazed to find a slit on the orange "valve". Replaced the valve itself this time with a spare one from one that was not torn made by BMW. Seemed to work for a while but within 2 weeks it came back. It is not damaged but the engine has been burning oil. PCV made some odd noises from the bleed hole at the bottom portion of it. FCP has that lifetime warranty but I may want to go ahead and buy a BMW original one now.

[K927A]

Hate to bump an old thread but I'm having very similar issues. I did the timing job/valley pan last year, about 10-15k miles ago. Replaced all the same things as the OP, with the exception of the Vanos

Everything ran fine at first, but then I also started getting fouled plugs on #7&8 regularly. Sucking down several quarts every 500-700 miles.

I've been also losing coolant (like a gallon every couple days) and getting misfires on other cylinders and was suspecting head gasket or cracked head but changing the plugs in the affected cylinders (which honestly looked clean) fixed the misfires issue, plenty of power on tap. Oil looks clean, coolant has some debris floating around in it but no oil.

Having the same weak starter issue, I think the motor itself is just going out, that happens cold or warm but not hot; it'll start cranking weakly then just stick almost as if the engine is seized. It takes a few tries but eventually budges and starts normally. I also have an occasional warm start issue, where it cranks easily but takes a LOT of cranking and WOT to get it to run (fuel pump/vapor lock perhaps?). The oil burning remains a mystery.

It's my DD so before I start tearing things down again, I'm hoping to get more specific ideas where to look. Still have yet to run current compression, leakdown, and coolant pressure tests.

[edjack]

Why are you waiting to do these tests?

How did your 325i sprout two more cylinders?

[K927A]

Just haven't had a free weekend to play with it yet, not waiting particularly.

Lol it didn't this is for my '01 540i/6

[Manny G.]

So this thread came up when I was searching for info on an issue my E38 is having with very similiar symptoms.

Started out with fouled plugs and a lumpy idle, occasional puff of smoke on startup.

Did oil change to 20w-50 (I live in South Florida). I also changed the CCV for a Meyle made version.

Seemed to have worked for maybe a week or so, then the puffs of smoke on startup showed up again.

Checked for suction at the dipstick, no suction or strange noises when the dipstick is pulled.

Occasionally get misfiring cylinders, it smooths out and goes away so this is intermittent.

I'm thinking the OSV could be bad, but if it was I think I would hear the suction noise at the dipstick.. no? It was not replaced when the timing chain guides were done.

I started to think it was the valve guides, but not entirely convinced it's that. Also considered that it was fuel from the EVAP system that was lingering too much fuel vapor in the manifold... not entirely convinced it's that either.

My next step is to pull off the throttle body and check to see how much oil is pooling up in the manifold, if any. But if there isn't any oil there... I'm kinda stuck? No clue where to go from here. If the internal OSV is dead, I'm converting to E53 X5 oil separation setup.

[jicaino]

So this thread came up when I was searching for info on an issue my E38 is having with very similiar symptoms.

Started out with fouled plugs and a lumpy idle, occasional puff of smoke on startup.

Did oil change to 20w-50 (I live in South Florida). I also changed the CCV for a Meyle made version.

Seemed to have worked for maybe a week or so, then the puffs of smoke on startup showed up again.

Checked for suction at the dipstick, no suction or strange noises when the dipstick is pulled.

Occasionally get misfiring cylinders, it smooths out and goes away so this is intermittent.

I'm thinking the OSV could be bad, but if it was I think I would hear the suction noise at the dipstick.. no? It was not replaced when the timing chain guides were done.

I started to think it was the valve guides, but not entirely convinced it's that. Also considered that it was fuel from the EVAP system that was lingering too much fuel vapor in the manifold... not entirely convinced it's that either.

My next step is to pull off the throttle body and check to see how much oil is pooling up in the manifold, if any. But if there isn't any oil there... I'm kinda stuck? No clue where to go from here. If the internal OSV is dead, I'm converting to E53 X5 oil separation setup.

Sounds like a bad OSV. They have a hard hose on the top end (the part that connects the plastic funnel with the aluminum elbow) that sometimes cracks and your SOL even if you have a working CCV. It just won't stop ingesting oil and you get occasional lumpy idle and no real reaction when you pull the dipstick with engine running (it should start stuttering) Have you measured vaccuum in the intake manifold? You should have reduced intake vaccum if the OSV neck is toast. Like 15 to 16" Hg. ballpark